Signaling
molecules involved in the transition of growth to development of Dictyostelium
discoideum

Hina
A Mir, Jyotika Rajawat, Shalmali Pradhan & Rasheedunnisa Begum

The social amoeba Dictyostelium discoideum, a powerful paradigm provides
clear insights into the regulation of growth and development. In addition to
possessing complex individual cellular functions like a unicellular eukaryote,
D. discoideum
cells face the challenge of multicellular development. D. discoideum
undergoes a relatively simple differentiation process mainly by cAMP
mediated pathway. Despite this relative simplicity, the regulatory signaling
pathways are as complex as those seen in metazoan development. However, the
introduction of restriction-enzyme-mediated integration (REMI) technique to
produce developmental gene knockouts has provided novel insights into the
discovery of signaling molecules and their role in D. discoideum
development. Cell cycle phase is an important aspect for differentiation of D. discoideum, as
cells must reach a specific stage to enter into developmental phase and specific
cell cycle regulators are involved in arresting growth phase genes and inducing
the developmental genes. In this review, we present an overview of the signaling
molecules involved in the regulation of growth to differentiation transition
(GDT), molecular mechanism of early developmental events leading to generation
of cAMP signal and components of cAMP relay system that operate in
this paradigm.

In
the present study tetanus toxoid (TT) loaded liposomes and diphtheria toxoid
(DT) loaded liposomes were prepared by reverse phase evaporation method and
after combining these two vaccines the potential advantages were investigated.
Prepared systems were characterized for the size, shape and entrapment
efficiency. SDS-PAGE analysis of TT and DT was also performed. The selected
liposomal formulations were administered subcutaneously to Balb/c mice and their
immune responses were determined using ELISA after 15, 30, 45 days. After
boosting the maximum immune response was observed after 45 days and was found to
be 0.831 and 0.749 for TT loaded liposome and DT loaded liposomes respectively.
When the mice were immunized subcutaneously with the physical mixture of TT
loaded liposomes and DT loaded liposomes the immune response for the combination
vaccine was found to be 1.44 and 0.741 for the TT and DT respectively. The
result showed that the immune response of TT increased when it was combined with
DT in liposomes. This confirms adjuvantcity of DT vis-a-vis immunogenicity.
Thus, carrier mediated cocktail vaccination holds promise for clinical
applications.

Endometrium of GnRH treated group resembled with
pregnant group and endometrial thickness in these groups significantly increased
in comparison with non-pregnant group.In GnRH treated animals, most of
histomorphological changes in epithelial cells, glands and stroma of uterus was
similar to pregnant group. The results revealed that mammalian form of GnRH
exerted endometrial change in guinea pig almost similar to those occur in normal
pregnant animals and its administration prior to implantation may improve
pregnancy rate following embryo transfer.

Time-dependent effect of benzene, a potent carcinogenic
industrial solvent, on lipid peroxidaiton and associated mechanisms has been
studied in liver and kidney of rats. Significant differences were observed in
the values of urinary phenol, microsomal malondialdehyde, reduced glutathione
(GSH) and cytochrome P4502E1 in rats treated
with benzene in morning and evening hours. Higher were the values for urinary
phenol and hepatic microsomal malondialdehyde in rats administered benzene in
evening hours. Contrarily, higher were the values for GSH and cytochrome P4502E1 in rats treated with benzene in morning hours.
Increased microsomal lipid peroxidation has been attributed to low GSH status,
whereas increased phenol concentration could be related to low activity of
cytochrome P4502E1 in the liver of rats in
evening hours. It is concluded that circadian rhythmicity in hepatic drug
metabolizing enzyme system and GSH contributes in toxicity of benzene. The
results are important from occupational health point of view.

Paraffin baiting system for demonstration
of growth and biofilm production in Pseudomonas aeruginosa

Received 14 June 2006; revised 16 October 2006

Pseudomonas
aeruginosa is one of the
commonest pathogens among the pseudomonads. This organism can grow in minimal
nutritional requirements. Because of the ability of pseudomonads to grow on
paraffin is not commonly found among other human pathogens and the primary human
pathogen being P.aeruginosa, we studied the adaptation of this organism
to paraffin baiting system for growth and biofilm formation. Strains were tested
for the capacity to use paraffin as the sole source of carbon using Czapek’s
minimal salt medium. Of the 53 clinical isolates of P. aeruginosa, 20 strains exhibited growth by 24 hrs and 42 strains by 48
hrs. The remaining strains did not show any growth in the paraffin baiting
system. The oxidase test with the paraffin baiting system was also performed.
This simple and inexpensive method can be used to isolate and demonstrate the
biochemical and biofilm forming capacity of the organism.

Osmotic adjustment increases water
uptake, remobilization of assimilates and maintains photosynthesis in chickpea
under drought

P S
Basu, Masood Ali & S K Chaturvedi

Received 25 July 2006; revised 10 October 2006

Eight chickpea advanced breeding lines
(ABLs) and their parents were evaluated for osmotic adjustment (OA), leaf
carbohydrates and gas exchange under dryland field . These (ABLs) were derived
from crosses between CTS 60543 ´ Kaniva and Tyson ´ Kaniva. Mean leaf water potential (LWP)
fell down from –1.00 MPa at pre-stress level to about –2.25 MPa during terminal
stress. Relative water content (RWC) showed periodic changes with alternate
decrease or increase at certain interval, which also influenced the values of OA
(low or high) in number of genotypes e.g. Kaniva, CTS 60543, Tyson and M 75.
Significant variation in OA ranging 0.45 to 0.88 MPa was observed at high level
of stress at –2.5 MPa. However, none of the genotypes showed stability of OA
over the period of stress. Leaf starch declined even at mild stress (LWP,-1.6
MPa) resulting in an increase in hexose sugars and activation state of
sucrose-phosphate synthase (SPS) that led to accumulation ofsucrose. Both
photosynthesis (Pmax) and transpiration
decreased concurrently in two chickpea lines M 129 and Tyson with increasing
water stress. However, rate of decline in the photosynthesis slowed down even
drought was further intensified. The observed periodic changes in OA, RWC and
photosynthesis appeared to be associated with drought-induced changes in SPS and
carbohydrates which modify water uptake of the leaves.

A
protocol for rapid multiplication of Adhatoda vasica has been developed through nodal
explants from field grown mature plants. The maximum number of shoots, i.e.,
7.75 + 0.392 differentiated from split nodal halves
on MS medium supplemented with BA (10.0 mg/l) during 4 weeks of culture. Maximum
number of shoots formed per explant increased to ca. 30 within 6 weeks of
subculture on medium containing BA (1.0 mg/l) and Kn (1.0 mg/l). The isolated
shoots rooted 90% in MS medium containing IBA (0.1 mg/l) in 2 weeks. The rooted
plantlets were successfully transferred to soil in glasshouse and subsequently
in field. The plantlets rooted in liquid medium did not survive, but those
rooted on solid medium showed more than 75% survival. In vitro raised
plants grew successfully ex vitro till flowering.

Curcuma longa as feed additive in broiler birds and its
patho-physiological effects

P
Kumari, M K Gupta, R Ranjan, K K Singh & R Yadava

Received 7 March 2006; revised 30 August 2006

Broiler birds (Vencob chicken of 3 days old) when given
feed mixed with powdered rhizome of Curcuma longa(CL; @ 1 g/kg) for 42 days of age, showed significant
decrease in serum uric acid and albumin as compared to control, whereas
significant increase was recorded in the level of serum total protein and
globulin. Level of serum glucose, alkaline phosphatase, aspartate amino
transferase and calcium showed no significant variation between the two groups.
Micronutrient assay revealed significantly higher level of manganese, zinc, iron
and copper in treated group as compared to control group. HA/HI test revealed
better humoral response against RD vaccine in CL administered birds.
Haematological study showed significantly higher haemoglobin and absolute
neutrophil count in treated group. Addition of CL as feed additive also resulted
in better growth rate, feed consumption and F:C efficiency in the treated birds.
Thus, it could be concluded that powdered CL might be a useful feed additive,
since it enhanced the F:C efficiency and had nephroprotective
properties.

Characterization of antimicrobial
compounds from a common fern, Pteris biaurita

A K
Dalli, G Saha & U Chakraborty

Received 29 May 2006; revised 5 December 2006

Methanol extract was prepared from the fronds of
Pteris biaurita
and partial purification was done by solvent partitioning with diethyl ether and
ethyl acetate, followed by hydrolysis and further partitioning with ethyl
acetate. The three fractions, thus obtained were bioassayed separately against
five test fungi- Curvularia lunata, Fomes lamaoensis,
Poria
hypobrumea, Fuasrium oxysporum and a bacterium- Bacillus pumilus,
by spore germination, radial growth and agar cup techniques. Results revealed
that ethyl acetate fraction (III) contained the active principle. TLC plate
bioassay of the active fraction revealed inhibition zone at an Rf of 0.5-0.65. Silica gel from this region was
scraped, eluted in methanol and subjected to UV-spectrophotometric analysis. An
absorption maxima of 278 nm was recorded. HPLC analysis of TLC-eluate revealed a
single peak with retention time of 8.1 min. GC-MS analysis revealed six major
peaks in the retention time range of 7.2-10.9 min. Comparison with GC-MS
libraries revealed that the extracts may contain a mixture of eicosenes and
heptadecanes.

Effects of polyherbal formulation
‘ImmuPlus’ on immunity and disease resistance of Indian major carp, Labeo rohita at
different stages of growth

Jaya
Kumari, P K Sahoo & S S Giri

Received 6 June 2005; revised 14 July 2006

A series of experiments were performed to
determine the impact of polyherbal immunomodulatory formulation ‘ImmuPlus
(AquaImmu) on growth, immunity and disease resistance of rohu (Labeo rohita), one
of the Indian major carp at different stages of growth. Rohu larvae were fed on
plankton, ImmuPlus-mixed compound feed, and plankton plus ImmuPlus-mixed
compound feed (ImmuPlus added at three dose levels of 0.25, 0.50, and 0.75 g/kg
feed) from 4th day of hatching to 14th day. ImmuPlus-mixed diets enhanced growth of
larvae, survival and disease resistance against Aeromonas
hydrophila challenge, compared to only plankton-fed group. In two other
experiments, advanced rohu larvae and fingerlings were fed with ImmuPlus-mixed
compound feed (at 0, 0.5, 1.0 and 2.0 g/kg) for 15, 30 and 45 days. At the end
of 45 days for advanced larvae and 30 days for fingerlings, the fish fed with
ImmuPlus at 1.0 g/kg level showed significantly higher growth and disease
resistance against A. hydrophila challenge. In a separate experiment,
juveniles of rohu were fed with 1 g/kg of ImmuPlus incorporated feed for 15 and
30 days. At the end of the trial, the ImmuPlus fed fish showed enhanced
non-specific immunity (as measured through nitroblue tetrazolium reduction
assay, serum lysozyme activity, serum haemolysin titre and resistance against A. hydrophila
challenge in non-vaccinated fish as well as specific immunity levels (as
measured through bacterial agglutination titre against A. hydrophila in
vaccinated fish). Incorporation of ImmuPlus at 1 g/kg level in the diet of rohu
may be beneficial for enhancing disease resistance.

G.gynandra
extract was found to potentially diminish the rate of lipid peroxidation, with a
significant increase in the levels of enzymatic (superoxide dismutase, catalase
and glutathione peroxidase) and non-enzymatic (reduced glutathione vitamins E
and C, and uric acid) antioxidants, which were found, altered during aflatoxin
B1 (AFB1)
injection. The result confirmed that G.gynandra extract exerts its chemopreventive efficacy
by preventing the rate of lipid peroxidation and influenced the enzymatic and
non-enzymatic antioxidants in AFB1 induced male
albino rats.